1. Field of the Invention
The present invention relates to an image processing apparatus which comprises an image reading unit and manages image data read by the image reading unit, a control method thereof, and a program.
2. Description of the Related Art
As the Electronic Documents Act has come into effect, even digitized documents obtained from paper documents, the large volume of which is flooding offices, are regarded as legally valid if they are saved/managed under predetermined conditions. The “predetermined conditions” change between the government offices. A main condition that is commonly defined is that “a document should be managed by a system capable of: clarifying the responsible person who has digitized the paper document, guaranteeing that the digitized document is not altered, and searching for the document”.
Especially, the National Tax Administration Agency strictly applies this condition and also defines a condition that an audit target document such as a receipt should be digitized within a predetermined period from its issue date. There is also a supplementary condition so that the “predetermined period” should be defined on the basis of a flow such as a business flow by the end user company that manages documents.
To comply with this law (ministerial ordinance), systems offered by manufacturers to scan a paper document and save it in a paper document add an electronic signature to image data immediately after scan for paper document digitization. This function clarifies a responsible person who has digitized a paper document. Moreover, addition of a time stamp guarantees absence of alteration.
Generally, every time a time stamp is added, the company that provides the time stamp service charges the end user for it, and the end user pays the charged amount.
A prior art is disclosed in Japanese Patent Laid-Open No. 2001-117820. Japanese Patent Laid-Open No. 2001-117820 has as its object to provide a method and apparatus for more safely managing the original of an important digitized document. In Japanese Patent Laid-Open No. 2001-117820, upon registering a document, registration certificate information is generated on the basis of electronic information such as a time stamp, device ID, and document ID. This allows to uniquely identify the document. Management/usage of documents is done by, e.g., updating the time stamp information of a document moved from another PC. In Japanese Patent Laid-Open No. 2001-117820, therefore, it is necessary to always add a time stamp upon document registration.
Every time a time stamp is added to guarantee the absence of alteration, the user is charged. However, if an audit target document is digitized after the elapse of the “predetermined period” from the issue date of the document, no legal validity is recognized regardless of a fee-charging time stamp, especially in the National Tax Administration Agency. In this case, there is (generally) no point in adding the fee-charging time stamp.
Some end users may want to always add a time stamp to guarantee the absence of alteration from the viewpoint of management rules of the company. Hence, the system preferably copes with both cases.
If the digitized document of an audit target has no legal validity, the company must also preserve its original paper document and present it at the time of audit. For this purpose, double management is required to manage digitized documents in the storage server and paper documents, resulting in cumbersome management.
If an enormous number of digitized documents exist, the system is preferably able to easily search for an audit target document to save time and effort in audit.